Master pin for endless track mechanism



Sept. 13, 194., R; ROMAN 4h74 MASTER PIN FOR ENDLESS TRACK MECHANISMFiled July `26, 1948 IN V EN TOR.

4 BMM/,

ATTRNEY Patented Sept. 13, 1949 MASTER PIN FOR ENDLE SS TRACK MECHANISMi I Randall Raman, renna, lli-.,lassignor to' caterpillar Tractor Co.,Peoria,

of California Ill., a ycorporation Application July 26, 194s,` serialNo. 46,664 j This invention relates to master pins `or removable pins ofthe kind used in chains and other articula-'ted devices. The inventionis adapted lfor use with the articuiatedfendless track of a tracktypevehicle and will be described herein by referenc'e to such use thoughits application in other environments will' -be readily appreciated'from this description.

In an endless track for track-type vehicles comprising a plurality oftrack shoes pivotally connected by means of pins, it is conventionalpractice to provide one master pin in each track assembly which can bereadily removed separating the track thus permitting its removal fromthe vehicle. Usually such master pins are provided with a suitablerecess in each end of the pin for the reception of a tapered plug, whichwhen driven into the recess causes the track pin to expand forming atight iit with the associated track shoe. Each plug is provided with athreaded socket for the reception of a suitable puller for removing theplugs from the master pin prior to removal of the track from theVehicle. Due to the environment in which the track operates, the plugsoften become corroded and are diiiicult to remove. Even under the mostsatisfactory conditions, a special puller is required which is often notavailable in the field.

It is, therefore, an object of this invention to overcome theabove-mentioned diiliculties by providing a master track pin, the endsof which can be expanded or contracted by means of tapered plugsarranged in such a manner that they can be removed by means of a simpledrift or punch, Other objects and advantages of this invention are madeapparent in the following specification wherein reference is made to theaccompanying drawings.

In the drawings:

Fig. 1 is a side elevation of a part of an endless track mechanismillustrating the manner in which the ends of the track may be connectedby means of the present invention,

Fig. 2 is a sectional view taken along line II-II of Fig. 1, and

Fig. 3 is a sectional view taken along line III-III of Fig. 2.

Fig. 1 of the drawings illustrates a part of a track mechanismcomprising a plurality of ground engaging track plates I0, each of whichis rigidly secured to a pair of spaced parallel track links I I as bybolts I 2. Each pair of track links is pivotally connected by means oftrack pins I3 to an adjacent and cooperating pair of links in such amanner that a chain is formed. The ends of the 5v Claims. (Cl. 74-251)chain are pivotally connected by means of a master pin, illustrated atI4, `forming lan endless chainwhich is adapted to be trained over adrive sprocket and idler 'sprocket as is customary in aV track-typevehicle. It is to the constructionof this master pin that this inventionis directed.

As is v`best illustrated in Fig. `2, the master pin I4 is disposedwithin suitable apertures provided in the track links II, forming apivotal connection between the links on adjacent track plates. A trackpin bushing I5, the ends of which are pressed into suitable openings inone pair of track links, is disposed about the track pin, and serves asa spacer between the track links, as well as acting as a bearing topermit rotation of the track pin.

Pin I4 is provided with an axial bore I6, the ends of which terminate intapered seats I'I and I8. Slots I9 are provided at the ends of the pinin positions to intercept the tapered seats and to permit the ends ofthe pin to be expanded. The seat I'I is adapted to receive a taperedplug 2 I, the maximum diameter of which is less than the diameter of thebore I6, permitting it to be inserted in the seat I'I from the oppositeend of the pin through the bore I6. The plug 2I is then forcedoutwardly, causing the end of the pin to be expanded forming a tight twith the track link embracing this part of the pin. The seat I8 isadapted to receive a tapered plug 22 having a minimum diameter as greator greater than that of the bore I6. When the plug 22 is forced,

inwardly into the seat I8, the adjacent end of the track pin is expandedforming a tight fit with its cooperating outer track link.

When it is desired to remove the master pin I4 in order to separate thetrack chain, the tapered plug 2| may be driven from its seat by means ofa suitable drift or punch permitting the adjacent end of the track pinto be contracted. The tapered plug 22 is removed in the same manner bycontinuing to force the plug 2l toward it. With this new and improvedconstruction of the master pin, the expanding plugs can be easilyremoved, regardless of condition, without the necessity of special toolsof any kind.

The tapered seats I'I and. I8 are for convenience preferably made asparts of the same taper and obviously the wall of the taper could becontinued throughout the entire length of the pin though manufacturingconsiderations indicate difculty in disassembly of the parts is likelyto occur.

I claim:

1. A hollow hinge pin or the like having bearing support adjacent itsopposite ends comprising seats for taperedplugs adjacent each end of thehinge pin for expanding its ends, said seats being tapered in the samedirection anda plug received by one seat of a size to pass freely thoughthe hollow pin and the other seat.

2. A hollow hinge pin having expandable .rends for engagement withsupporting Ybearings com#l prising a tapered plug adapted to t in eachend to expand it, one of said plugs beingflarger-thanfv: Y.

the other and both being received with their seats in the same directionwhereby the smaller plug may be unseated and driven 'out through thehollow pin. Y q

3. A hollow hinge pin having expandable ends for engagement withsupporting bearings comprising a tapered plug adapted to t in each .endto expand it, said pin having seats for saidlplugs adjacent its end andformed as a continuation of the same taper whereby a small plug will tone end and a larger plug the other end.

4. A hollow hinge pin having expandable ends 1o Y than the other and thetapers converging in the rsmaller plug. Y

for engagement with supporting bearings cor-l# prising a tapered plugadapted to t in each end to expand it, said pin having seats Vfor saidplugs adjacent its end and formed as a continuation of the same taperwhereby a small plug will t one end and a larger plug the other end andwhereby both plugs may be removed by driving ,the smal plug in thedirection of its large end. Y

5. A hollow pin with expandable ends, a tapered plug for each end, oneplug being smaller same direction and toward the end with the RANDALLROMAN.

REFERENCES CITED Thefollowing references are of record in the le of'thispatent:

UNITED STA'IES` PATENTS 824,204k France Nov. 3, 1937

